Sewing-machine work-handling mechanism.



]. WHITELAW.

SEWING MACHINE WORK HANDLING MEGHA NISM. APPLICATION FILED NOV. 24. m3.

1,1 98,800. Patented Sept. 19,1916.

3 SHEETS-SHEET I.

J. WHlTELAW.

SEWING MACHINE WORK HANDLING MECHANISM.

APPLICATION FILED Nov. 24. I913.

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SEWING MACHINE WORK HANDLING MECHAMSM.

APPLICATION FILED NOV- 24. 1913.

1 1 98,800 Patented Sept. 19, 1916.

3 SHEETSSHEET 3.

n 23 I I neasea' (717mm Wlfite/ma WZ/m a mam JAMES WHITELA-W, OF ST. LOUIS, MISSOURI.

SEWING-MACHINE WORK-HANDLING- MECHANISM.

Application filed November 24,1913.

To all whom it may concern:

Be it known that I, JAMES WHITELAW, a citizen of the United States, residing at St. Louis, State of Missouri, have invented certain new and useful Improvements in Sewing Machine Work Handling Mechanism, of which the following is a specification.

My invention relates to sewingmachine work handling mechanism and in some of its features more particularly to blind stitch sewing machines.

The general object of my invention is to provide a simple and eflicient feed andplun ger mechanism, and operating means therefor, for cooperation with a stationary presser foot to present portions of the work to be stitched in a presser foot opening, holding the goods at the time of such presentations snug and taut around the bender and handling the work uniformly and with certainty under high speed conditions.

Another object of my invention is to provide simple and effective construction enabling the moving parts of the work-handling mechanism all to be displaced from normal plane, as to permit insertion or removal of work, at any time in the cyclic operation of the parts.

In the drawings wherein I have illustrated an embodiment of my. invention F igure 1 is a front elevation of a blind stitch sewing machine, with parts of the frame broken away to expose the work handling mechanism; Fig. 2 is a section on line 22 of Fig. 1; Fig. 3 is an enlarged end view of the work handling mechanism and associated presser foot parts; Fig. 4 1s a section on line H of Fig. 3; Fig. 5 1s a cross sec tion on line 55 of 1; Fig. 6 is a detail of the feed-length controlling cam; Fig. 7 is a. section of the plungershaft on line 77 of Fig. 1; Fig. 8 is a section on line 88 of Fig. 4; and Fig. 9 is a section on line 99 of Fig. 3.

The blind stitch sewing machine shown in the drawinghas a frame 10 comprising the upper and lower arms 11 and 12, an intervening post or standard 13 and in general provides suitable stitch forming mechanism 14 herein shown as of the chain stitch type involving a curved reciprocating needle 15 and a complemental looper mechanism 16, both arranged to work above a stationary presser foot 18 which has therein an appro Specification of Letters Patent.

Patented Sept. 19, 1916.

Serial No. 802,732.

priate aperture 19 through which the goods .may be presented to the needle.

With the character of the stitch forming mechanism, the present invention is not concerned, but a stitch forming mechanism, of which fragments are illustrated in Fig. 1 is specifically shown and described in my copending application, Serial No. 802,733, filed November 24, 1913.

20 is a main shaft extending through the upper arm 11 of the machine and driven by the hand wheel pulley 21, said main shaft serving to actuate the stitch forming mechanism and having operating connections through mechanism contained within the post 13 with the work handling mechanism carried by the lower arm 12. The lower arm 12 is hollow from its juncture with the post 13 to an integral end block or head 22 preferably arranged slightly out of alinement with the presser foot 18 so that mechanism supported outside of said block 22 may aline with the presser foot, a detachable cover 23 secured on the block22 by screw 24 may inclose the space in which the working parts move.

The goods handling mechanism, generally indicated at 25, comprises in the specific construction shown a feed dog 26 to cooperate with the under side ofthe presser foot, a clamp member 27 coordinated with said feed member and also cooperating with the under side of the presser foot 18 and a plunger 28 cooperating with the aperture 19 of the presser foot 18 to present a bend in the goods therethro'ugh tothe operation of the needle, with actuating connections and regulating devices for these parts.

A feed dog 26 shaped to provide separated side points 26 receives a four-way motion to perform its effective feeding operation by moving toward therear of the ma chine. Specificallydog 26 has a rearward, substantially horizontal extension 30 .pivotally connected as at 31 with ,a substantially vertical crank 32 which is fast on a driving rock shaft 33, therocking of which in a horizontal direction contributes the forward and backwardmotions to the feed. For elevation and depression, the feed member has a connection between its ends as at, 34 to a substantially vertical link 35, said link 35 pivotally connected as at 36 between the ends of a lever 37, one extremity of which is pivotally connected as at38 to a generallyhorizontal'crank arm 39 carried by a rock shaft 40, so that the rocking of the shaft elevates and depresses the crank arm 39 and with it the attached end of the lever 37. The remote end of said lever 37 is pivoted as at 41 to a link 42 suspended from a pivot 43 which, I prefer, shall receive sup port from a vertically movable carrier. Disregarding possible movement of the suspension point 43 it will be obvious that rocking of the shaft 40 serves to elevate or depress the feed dog 26 with lever 37, working on 41 as a fulcrum and by appropriate timing v.of the rocking operations of shafts 33 and 40, the feed part may be made to effect its desired four-way cycle of movement. V The clamp member 27, is preferably formed with a short head serrated transversely as shown in Fig. 4'and disposed between two tooth points 26 of the feed dog 26, so as to work in a central slot'of said feed dog. Said clamping head is intended, in the normal working operation, to clamp the goods against the under side of the presser foot during the time when the feed dog is out of engagement with the goods and to be removed from holding position when the feed dog is exerting its feeding influence. To this end the clamp member and feed dog are inter-related for appropriate co6peration controlled by the operating mechanism for the feed dog. The clamping head 27 is carried by a vertical post 45, sliding against loohead 22 and having guiding wings 46 at its sides working in grooves made therefor in the retaining-plates 47, said sliding post constituting a carrier afiording bearing for the pivot 43 on which the link 42 is suspended. 105 I provide in conjunction with the mechanism described means normally to hold the post 45 in raised position but to effect its depression at will. Specifically I provide a rod 50 extending along the front of the mallochine through a suitable bearing 51 near the. uncture of the arm 12 and post 13 and through a bearing in the said block 22, and on the extremity of said arm I provide a finger 53 engaging in a recess 54 provided 115therefor in the outer face of the post 45. This rod is appropriately provided at its other end with a lever 56 to which the customary kneelift may be attached and said lever is acted on by a spring 57 normally 120tending to rotate the rod 50 and through the finger 53. to lift the. post 45.

The relation of the parts and the throw of the rock shaft 40 are such that the clownward sweep of crank 39 when the feed dog 1'25has completed its feeding movement, causes lever 37 to fulcrum on pivot 41 and through link 35 to retract the feed dog from the presser foot, but when the. feeddog is raised, by the upward sweep of the crank 39, for

130commencement ofthe feeding action'of thedog, said feed dog comes in contact with the under side of the presser foot before the throw of crank 39 is completed and then the lever 37 fulcruming on the pivot 36 acts as a lever of the first class to draw downward upon the link 42 thereby withdrawing the clamp 27 from engagement with the under side of the presser foot or with the work, as best shown in Fig. 3.

l he link arrangement shown permits the post 45 to be lowered, depressing the sub stantially vertical link 42 and thereby drawing down the link 35 and the feed dog 26 to a point where the feed dog and clamp member are both presser foot sufficiently for insertion of the work between the feed and clamp parts and presser foot. hen so withdrawn, operation of the machine to actuate the rock shaft causes the feed dog to go through an idle or useless four-way motion but it will be apparent that by this arrangement the withdrawal of the feed dog and clamp from the presser foot to permit insertion of the work may be effected while the machine is running, if desired, at any part of its cycle of operation.

The plunger 28 is carried by and bodily moves with the post 45, but may move a limited distance with respect to said carrier or post 45. Specifically the plunger 28 is a cylindrical stem hearing at its upper extremity a properly shaped head 60, shaped to form a ridge in the goods transverse to the path of the needle, and at its lower end having an enlargement or base 61. Said stem fits within an appropriate bore 62 in the post 45 and is normally depressed by a spring 63 acting between an upper shoulder of the bore and the base 61 to force said plunger down into the post to the full extent permitted by the play at pin 64 carried by the stem within a slot 65, cut in the upper portion of the post 45. The lower end of the plunger base 61 projects below the post 45 to such distance that in the normal operation of the device full elevation of base 61 of the plunger may project head 60, against the tension of spring 63, to a sufficient height'to present a node of goods through the presser-foot opening 19 to the needle.

For actuating the plunger to give it its movements relative to the clamping post 45 which carries it, I provide the rocking shaft 66 extending longitudinally of the frame, and bearing on its extremity a crank arm 67, the extremity of which, acting against the plunger base 61 to elevatethe plunger, preferably carries a pin 68 extending longitudinally of the machine into a recess 69 provided therefor in the end-block 22, the range of throw of said crank arm 67 being regulable by an adjusting screw 70 extending from an exposed position .upon the arm withdrawn from the down through the end-block 22 into recess 69 to form an adjustable stop for pin 68.

It will be understood that the several rock-shafts 33 40 and 66 are operated in appropriate timed relation by mechanism at the rear end of the machine, driven by the main shaft, and as has heretofore been stated the cyclic operations of the two rockshafts 33 and 40 are not interfered with at all by the movement of the feed and clampmechanism from normal position to depressed position for goods-insertion. The rock-shaft 66 tends in its normal operation invariably to raise the plunger stem to a predetermined position, but I prefer that this elevating action shall be permitted by the plunger only when the cloth holding and feed mechanism are in normal relation to the work, the movability of the plunger with respect to the post 45 being limited by the extent of projection of base 61 of the plunger from the bottom of the post. In order, therefore, that parts may not be broken when extra heavy work is inserted or when the feed-dog and clamp-post are depressed by the operation of lever 56 while the machine is running, the driving connections with the plunger operating crank 67 of the driving gearing should include a yielding part and I prefer that the shaft 66, intermediate its ends, be flattened as at 66" (Fig. 7) so that said shaft may operate as a strong torsion-spring. Thus, although positive rocking movement is imparted to the rear end of shaft 66, when its crank-arm 67 encounters the bottom of clamp post 45 while the latter is depressed below normal position the torsion-spring action of the shaft 66 yields under the opposing power and resistance and prevents breakage of the parts, the plunger not being raised far enough to prevent goods-insertion.

The three shafts, 33, 40 and 66, are all preferably driven by an eccentric on the main shaft. The rocking motion of shaft 33, which imparts the fore-andaft motion to the feed dog 26 should be variable in or der that the feed between stitches may be varied, and to this end I provide means for adjustment of the throw of the eccentric, on the main shaft, which operates the rockshaft 33. Specifically 80 indicates a disk on the main shaft 20 secured thereon as by screws 81, said disk having in its face a slide-way 82, in which is mounted a slide 83,

extending diametrically across the face of the disk, having a central opening 84 surrounded by a cam annulus 85 which, by adjustment of the plate transversely of the disk, may be thrown to different degrees of eccentricity to the shaft 20. The plate 83 is retained in its slide-way on the disk by engagement of the notch 86 in the edge of the plate under the head of the screw 87 carried by the disk, and for diametric adjustm nt of the plate I provide at one edge of the plate a flange 83 overhanging and bearing upon a'pair of springs 88 which are seated in a recess made to receive said flange 83 in the edge of the disk, said plate being adjustable against the tension of the springs 88 by a screw 89 extending through the flange 83 and into the body of the disk. Manifestly by adjustment of the screw 89 the eccentricity of the annulus 85 may be varied. The eccentric annulus 85 is engaged by an eccentric strap 90 carried by an arm 91 which makes pivotal connection as at 92 with a crank 93 on the shaft 33.-

As the throw of the rock shaft 10 which raises and lowers the feed need not be varied an ordinary eccentric 95 onthe main shaft 20 may be employed in conjunction with theeccentric strap 96 carried by. arm 97 which has pivotal connection 98 with the crank 99 secured to shaft 40. As has heretofore been pointed out variation in the throw of the plunger may be taken care of by the resiliency of the torsional shaft 66, and, therefore, I may employ to actuate said shaft 66 an ordinary eccentric 100 cooperating with the eccentric strap 101 carried by arm 102. In lieu of direct connection of said arm 102 with the crank arm 103 of the shaft 66, however, I prefer to employ an intermediate bell-crank lever 104, pivoted as at 104 to the frame, having one arm pivotally connected as at 105, to the arm 102 and its other arm pivotally connected as at 106 to a link 107 which is in turn-pivoted to the crank 103. The relation of these parts is preferably such that as the eccentric is passed over dead-center with respect to its arm 102 the bell-crank 104 is thrown to approximately its upper dead-center with respect to its link 107 so that the crank 103 on the shaft 66 is elevated to its maximum extent and held in such elevated position, so as to hold the plunger at substantially its highest position, for a material length of time in the cycle of rotation of the main shaft. This insures the maintenance of the plunger in elevated position for a suflicient length of time to give adequate opportunity for the needle to penetrate the goods to be stitched. which are supported on the tip of the plunger, before the shaft 66 is rocked to with draw the plunger-actuating crank 67 and permit the spring 63 to return the plunger to its lowest position within its carrying clamp-post. Also by properly prop0rtioning the parts an extended range of motion may be given to the rock-shaft so that the lever 67 when withdrawn will be thrown clear out of the way of the plunger-base 61 so as to not interfere with the full depression of the feed dog and the clamp-head carrying with it the plunger. 7

While I have herein described in some deta l a p ific em odiment f my inventi n,

it will be apparent to those skilled in the art that changes might be made in the structure without departure from the spirit of my invention and within the scope of the appended claims.

What I claim is:

1. In a sewing machine the combination of a vertically movable carrier; a feed dog; two axially-fixed, unyielding rock-shafts therefor; cranks on said rock-shafts, one disposed to oscillate in a substantially horizontal arc and the other in a substantially vertical arc; pivotal connections between the first said crank and the feed-dog; and connections between the other said crank and the feed-dog'comprising a lever, two links pivoted at different points in the levers length, either to form the lever fulcrum, one said link pivotally connected to feed dog and the other said link pivotally connected to the carrier.

2. In a sewing machine, the combination of a feed dog; a vertically movable carrier; resilient means normally maintaining said carrier in raised position a rock-shaft having a horizontally-oscillating crank pivotally connected with the feed-dog, another rock-shaft having "a vertically-oscillating crank, a substantially horizontal lever connected With the last said crank, a link pivotally connected at its extremities to the mid-portion of said lever and to the feed dog, to impart vertical movement to the latter as the last mentioned crank oscillates; and another link connected to the extremity of said lever and to the vertically movable carrier; and means for depressing said carrier, whereby when the carrier is depressed the feed dog is lowered and may perform its cyclic operations under the action of the rock-shafts.

In testimony whereof I hereunto setmy hand in the presence of two Witnesses.

J. D. RIPPEY, L. C. KINesLAND.

/ Copie svof thisvpatentmay be obtained: for five cents each, by addressing the, Commissioner of Patent,

Washington, D. 0. 

